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[Qemu-devel] [PATCH v3 00/27] block: Lock images when opening
From: |
Fam Zheng |
Subject: |
[Qemu-devel] [PATCH v3 00/27] block: Lock images when opening |
Date: |
Thu, 28 Apr 2016 20:57:19 +0800 |
v3: Highlight is handling of image locks during close(3) and bdrv_reopen(). A
number of new patches are added consequently. Per patch change logs are:
[01/27] block: Add BDRV_O_NO_LOCK
Add Denis's rev-by.
[03/27] blockdev: Add and parse "lock-image" option for block devices
Add as root BDS option too.
[04/27] block: Introduce image file locking
Treat -ENOTSUP the same as empty .bdrv_lockf.
[05/27] block: Add bdrv_image_locked
New.
[06/27] block: Make bdrv_reopen_{commit,abort} private functions
[07/27] block: Handle image locking during reopen
New. Handle reopen. [Laszlo]
[08/27] osdep: Add qemu_lock_fd and qemu_unlock_fd
[09/27] osdep: Introduce qemu_dup
[10/27] raw-posix: Use qemu_dup
[11/27] raw-posix: Implement .bdrv_lockf
New. Handle close. [Daniel]
[12/27] gluster: Implement .bdrv_lockf
Add Niels' rev-by.
[13/27] qemu-io: Add "-L" option for BDRV_O_NO_LOCK
Update argument documentation. [Denis]
[18/27] mirror: Disable image locking on target backing chain
New. Target image is not locked.
[19/27] qemu-iotests: 140: Disable image lock for qemu-io access
[20/27] qemu-iotests: 046: Move version detection out from verify_io
[21/27] qemu-iotests: Wait for QEMU processes before checking image in 091
[22/27] qemu-iotests: 030: Disable image lock when checking test image
[23/27] iotests: 087: Disable image lock in cases where file is shared
[24/27] iotests: Disable image locking in 085
[25/27] tests: Use null-co:// instead of /dev/null
New. Several updates of testing to avoid image locking voilation.
[27/27] qemu-iotests: Add test case 153 for image locking
Add a number of new combinations.
Too many troubles have been caused by two processes writing to the same image
unexpectedly. This series introduces automatical image locking into QEMU to
avoid such tragedy. With this, the user won't be able to open the image from
two processes (e.g. using qemu-img when the image is attached to the guest).
Underneath is the fcntl syscall that locks the local file, similar to what is
already used in libvirt virtlockd. The difference is that libvirt locks byte 0,
we lock byte 1. Read only openings are mapped to shared locks.
The alternative locking API, flock(2), doesn't provide byte range locking and
is also forwarded to fcntl on Linux NFS mount points, so we'd end up
conflicting with virtlockd. Thus it is not used.
Gluster locking is also implemented wrapping glfs_posix_lock. The patch is
lightly tested.
All other drivers that don't implement .bdrv_lockf are always permissive and do
not check.
Fam Zheng (27):
block: Add BDRV_O_NO_LOCK
qapi: Add lock-image in blockdev-add options
blockdev: Add and parse "lock-image" option for block devices
block: Introduce image file locking
block: Add bdrv_image_locked
block: Make bdrv_reopen_{commit,abort} private functions
block: Handle image locking during reopen
osdep: Add qemu_lock_fd and qemu_unlock_fd
osdep: Introduce qemu_dup
raw-posix: Use qemu_dup
raw-posix: Implement .bdrv_lockf
gluster: Implement .bdrv_lockf
qemu-io: Add "-L" option for BDRV_O_NO_LOCK
qemu-img: Add "-L" option to sub commands
qemu-img: Update documentation of "-L" option
qemu-nbd: Add "--no-lock/-L" option
block: Don't lock drive-backup target image in none mode
mirror: Disable image locking on target backing chain
qemu-iotests: 140: Disable image lock for qemu-io access
qemu-iotests: 046: Move version detection out from verify_io
qemu-iotests: Wait for QEMU processes before checking image in 091
qemu-iotests: 030: Disable image lock when checking test image
iotests: 087: Disable image lock in cases where file is shared
iotests: Disable image locking in 085
tests: Use null-co:// instead of /dev/null
block: Turn on image locking by default
qemu-iotests: Add test case 153 for image locking
block.c | 69 +++++++++++-
block/gluster.c | 31 ++++++
block/raw-posix.c | 32 ++++--
blockdev.c | 23 ++++
include/block/block.h | 6 +-
include/block/block_int.h | 12 ++
include/qemu/osdep.h | 3 +
qapi/block-core.json | 6 +-
qemu-img-cmds.hx | 44 ++++----
qemu-img.c | 90 ++++++++++++---
qemu-img.texi | 3 +
qemu-io.c | 24 +++-
qemu-nbd.c | 7 +-
qemu-nbd.texi | 2 +
tests/drive_del-test.c | 2 +-
tests/nvme-test.c | 2 +-
tests/qemu-iotests/030 | 2 +-
tests/qemu-iotests/046 | 22 ++--
tests/qemu-iotests/085 | 3 +-
tests/qemu-iotests/087 | 6 +
tests/qemu-iotests/091 | 3 +
tests/qemu-iotests/091.out | 1 +
tests/qemu-iotests/140 | 2 +-
tests/qemu-iotests/153 | 191 ++++++++++++++++++++++++++++++++
tests/qemu-iotests/153.out | 266 +++++++++++++++++++++++++++++++++++++++++++++
tests/qemu-iotests/group | 1 +
tests/usb-hcd-uhci-test.c | 2 +-
tests/usb-hcd-xhci-test.c | 2 +-
tests/virtio-blk-test.c | 2 +-
tests/virtio-scsi-test.c | 4 +-
util/osdep.c | 215 +++++++++++++++++++++++++++++++++---
31 files changed, 986 insertions(+), 92 deletions(-)
create mode 100755 tests/qemu-iotests/153
create mode 100644 tests/qemu-iotests/153.out
--
2.8.0
- [Qemu-devel] [PATCH v3 00/27] block: Lock images when opening,
Fam Zheng <=
- [Qemu-devel] [PATCH v3 01/27] block: Add BDRV_O_NO_LOCK, Fam Zheng, 2016/04/28
- [Qemu-devel] [PATCH v3 03/27] blockdev: Add and parse "lock-image" option for block devices, Fam Zheng, 2016/04/28
- [Qemu-devel] [PATCH v3 02/27] qapi: Add lock-image in blockdev-add options, Fam Zheng, 2016/04/28
- [Qemu-devel] [PATCH v3 05/27] block: Add bdrv_image_locked, Fam Zheng, 2016/04/28
- [Qemu-devel] [PATCH v3 04/27] block: Introduce image file locking, Fam Zheng, 2016/04/28
- [Qemu-devel] [PATCH v3 07/27] block: Handle image locking during reopen, Fam Zheng, 2016/04/28
- [Qemu-devel] [PATCH v3 06/27] block: Make bdrv_reopen_{commit, abort} private functions, Fam Zheng, 2016/04/28
- [Qemu-devel] [PATCH v3 08/27] osdep: Add qemu_lock_fd and qemu_unlock_fd, Fam Zheng, 2016/04/28
- [Qemu-devel] [PATCH v3 10/27] raw-posix: Use qemu_dup, Fam Zheng, 2016/04/28
- [Qemu-devel] [PATCH v3 09/27] osdep: Introduce qemu_dup, Fam Zheng, 2016/04/28